The present invention relates to a series of novel piperidyl-triazine derivatives which are useful as stabilizers for synthetic polymers.
In recent years, a number of triazine derivatives have been proposed for use as polymer stabilizers, for example as disclosed in U.S. Pat. No. 4,108,829, No. 4,433,145, No. 4,400,505 and No. 4,461,861 and in Japanese Patent Application Kokai (i.e. as laid open to public inspection) No. 176 662/86. Of these, the closest prior art is believed to be Japanese Application Kokai No. 176 662/86, which discloses, inter alia, the compound 1,3-bis&lt;3-{2,4-bis[N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)ami no]-1,3,5-triazin-6-ylamino}propoxy&gt;-2,2-dimethylpropane and proposes its use as a polymer stabilizer.
In broad, general terms, the chemical structure of these prior art compounds, including that one specifically mentioned above, insofar as they are relevant to the compounds of the present invention, may be described as having a piperidylaminotriazinyl group attached via, for example, an amino group to an alkylene group, which itself may optionally be interrupted by certain specific atoms or groups. In the case of the prior art compounds, the alkylene group is interrupted by certain specific atoms or groups, such as an oxygen or sulfur atom or an amino group.
We have now surprisingly discovered a series of piperidyl-triazine derivatives in which the alkylene group is interrupted by a group of formula --OCO--, --COO--, --CONH-- or --OCONH--, which is unusual in this type of compound. These compounds have a very low volatility, and indeed, do not even volatilize to any great extent when the polymer containing them is heated. Moreover, they result in little blooming and additionally are excellent polymer stabilizers against heat and light.
The only compounds of this type that we have been able to discover having an alkylene group interrupted by groups similar to those in the present invention are disclosed in Japanese Patent Application Kokai No. 63570/87 and in United Kingdom Patent No. 2 136 805. Although these prior compounds are disclosed for use as polymer stabilizers, they differ from the compounds of the present invention in that they have a piperidylamino group attached directly to the alkylene group and lack the triazine group of the present invention. The compounds of the present invention have been found to be significantly more effective polymer stabilizers than these prior compounds.